Semester

Spring

Date of Graduation

2025

Document Type

Thesis (Campus Access)

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Human Nutrition and Foods

Committee Chair

Janet Tou

Committee Co-Chair

Nicole Waterland

Committee Member

Youyoun Moon

Abstract

Impact of Different Temperatures on Blueberry Fruit Size and Nutritional Quality

Background: Blueberries are the second most produced berry in the United States. Highbush blueberries are commonly used in production because of their large berries. Blueberries are considered a ‘superfruit’ because of its nutrient density and particularly, their high antioxidant content. Two Northern highbush have an optimal growing temperature of 20-25˚C. Northern highbush blueberry cultivars, ‘Jersey’ ripens late season while ‘Blueray’ ripen mid-late season.

Objective: To determine the effect of different temperatures on blueberry size and nutrient quality. The temperatures used were 18-28˚C to determine whether small fluctuations from the optimal temperature may affect fruit size, flavor, and nutritional quality.

Results: Cultivar differences in blueberry size and nutrition were influenced by temperature. ‘Blueray’ had larger berries, higher total soluble solids, and titratable acidity (TA), but lower fructose, suggesting a tarter berry with a higher total water-soluble vitamin content than ‘Jersey.’ Growing at temperatures slightly above or below optimal temperatures affected berry size, TA, antioxidant capacity, and biotin content. Blueberries grown at 28°C experienced heat stress with smaller fruit and reduced antioxidant and biotin levels. ‘Blueray’ was more temperature-sensitive, showing a significant size decrease at 20°C, while ‘Jersey’ was affected at 28°C.

Conclusion: Collectively, the results highlight that even small temperature fluctuations can impact blueberry nutrient and antioxidant content. By understanding the effect of temperature fluctuations on different cultivars, blueberry producers can select the cultivar most resilient to quality degradation caused by temperature variations. This is crucial with expected temperature extremes due to climate change.

Download

Share

COinS